The long term objective of this research is to engineer mammalian cells so that they have the genetic instructions to produce mature insulin at biological levels in response to extracellular glucose, as a major component of a bioartificial pancreas. The result will provide type I diabetics with an alternative to insulin injections. The creation of a bioartificial pancreas could help to lower the medical costs associated with type l diabetes and to provide type 1 diabetics with the ability to lead a life with less stringent medical attention. The approach in this research will be to add furin recognition sites to the proinsulin gene by double-stranded DNA mutagenesis. This proinsulin gene will be placed under the control of the S14 promoter which is tightly up-regulated by glucose. This S14 promoter/proinsulin gene on a plasmid will be cotransfected along with the furin gene into several different cell lines. The transfected cells normally express very little if any furin, therefore it is necessary to provide them with the furin gene to increase furin enzyme levels within the cell. This process will allow cells that normally do not have prohormone processing ability, the ability to produce and process a prohormone into a mature